Tailings Slurry Density Monitoring

A tailings circuit can contain several distinct slurry streams. Density at a thickener underflow, filter feed or transfer pipeline may support different operational decisions. Treating them as one generic “tailings density” application creates poor measurement locations and unclear acceptance criteria.

Define whether the signal is intended to support pumping, recirculation, filtration, water balance, transferred-solids calculation, monitoring or investigation. Then identify the stream and process state the sensor must represent.

• Source process and destination
• Normal, minimum and maximum density
• Solids, carrier liquid and composition changes
• Pipe size, material, orientation and fill condition
• Flow velocity, pressure and pump arrangement
• Air, settling, scaling and abrasive conditions
• Sampling and laboratory method
• Required display, logging, alarm or control use

The Grupo Mexico case describes an SDM ECO on a tailings-thickener underflow, combined with a flow meter for mass-flow calculations and tested through changes between water and slurry.

Rhosonics also reports an SDM used at Minera Poderosa on the discharge pipeline of a tailings thickener to support the subsequent filtering stage. The case describes the online signal being used within a control arrangement. These are examples of defined duties, not guaranteed results for every tailings circuit.

Changes in mineralogy, particle size, dissolved solids, temperature, entrained air and wear can affect measurement interpretation or calibration. Low-flow settling and partially filled lines can make a mechanically convenient point unrepresentative.

A density meter does not replace the site’s independent pressure, flow, geotechnical, containment or process-safety safeguards. Clearly define invalid-signal handling and the limits of any automated response.

1. Name the stream and destination. Avoid the ambiguous label “tailings line”.
2. Define the decision and users. Monitoring, pumping, filtering and mass-flow duties need different context.
3. Survey representative locations. Review fill, air, settling, abrasion, access, isolation and the relationship to flow and sampling.
4. Select and document the fitting. Match the current manufacturer integration to the actual pipe and maintenance duty.
5. Commission across the operating range. Include flush water, normal slurry and relevant changes with aligned reference samples.
6. Retain the evidence. Store configuration, calibration, sample, trend and process-context records for later review.

Continue to thickener underflow density measurement, the solids calculator or the installation and commissioning guide.

Can tailings density be measured continuously?

Yes, where a suitable technology, representative location and validation method are established for the specific stream. Rhosonics publishes several examples using its ultrasonic SDM range.

Does density alone give dry-solids throughput?

No. It must be converted using appropriate solids and liquid densities and combined with a suitable volumetric flow value. Units, location and timing must align.

What should be recorded at commissioning?

Record the physical installation, configuration, process state, reference samples, timestamps, related flow or pump signals, acceptance criteria and any exclusions.

Reviewed 10 September 2026 against the Rhosonics Grupo Mexico tailings-thickener case, Minera Poderosa case, current SDM ECO product information and operating manual. The cited outcomes are installation-specific.

Send PMA the stream description, circuit drawing, slurry range, pipework, flow and pump data, operating states, reference method and how the proposed density signal will be used.